2. To walk or run quickly as if you're late for something or you have to use the bathroom
3. A method used when running from authority figures
Origin: a combination of "book it" and "haul ass"
Also, booking ass, and less commonly book assing.
2. "Oh man! It's it good thing I booked ass or I would've been late to class!"
3. "The cops saw us doing recreational drugs. That's about when we booked ass"